Connections and quick-release couplings for the above purpose are disclosed in DE-U 1840515, DE-U 7918414, DE-A- 3429945 and DE-B 2757358. These specifications teach the use of a fixed connection between the eyepiece cup and the camera, which prevents the camera from rotating on the eyepiece cup. In many cases this makes the entire unit which consists of the endoscope and/or the lens unit thereof, the objective with quick-release coupling, and the camera awkward to handle, especially in circumstances where the point of access of the endoscope when in use, to a chosen area of tissue, needs to be varied, whilst the viewing position of the camera remains unchanged; for example for staunching bleeding, effecting coagulation or making an incision.
Although in principle the endoscope, when in use, may be rotated about its longitudinal axis to only a slight or to a restricted extent, such as when a coagulating-cutting loop is used for example, rigid attachment of the camera to the eyepiece cup of the endoscope lens unit, has the disadvantage that the image is simultaneously rotated, so that an endoscopic picture displayed by means of a monitor may cause the observer to become disorientated.
In order to correct such image reorientation the operating surgeon must interrupt the operation thereby increasing its duration and also, disturbing his concentration.